Privacy Film

Several years ago 3M developed a paper-thin, electrically sensitive Privacy Film, based on patents held by Kent State University and Raychem Corporation. Between two sheets of this film, a layer of liquid crystal was put and all are held between panes of glass to produce the Privacy Glass (Electrically switchable smart windows). When electricity is applied to this system, the liquid crystals line up and the foggy material becomes clear, when the current is withdrawn, it becomes opaque again. 

Reflective Window Films - A materiai appiied to window panes that controis heat gain and ioss, reduces giare, minimizes fabric fading, and provides privacy. These fiims are retrofitted on existing windows. 

JEANNIE Be respectful of the privacy of who you re covering, especially if you re making personal films. Even if you re doing a very intimate film you can do that. Unless there s some real evil that you re dealing with, I think that people need to be careful and respectful of whom the/re shooting. 

Plate 7 Privacy window using a polymer dispersed liquid crystal film (Courtesy of Marvin Windows Doors). 

Figure 6-28. With the touch of a button, interior windows can change from clear to translucent, using liquid-crystal TP polyester film. This window consists of a two-layer laminated GE Lexan sheet to protect an inner polyester film. This polycarbonate product is strong and mar and UV resistant. The film is able to switch electrically between a highly translucent state providing privacy, glare control, and shading to a clear state for good visibility.

Combining outstanding mechanical properties of the polymer film (high mechanical strength and flexibility) with interesting optical properties of liquid crystal (high optical anisotropy), the PDLC systems allow their use in various applications as flexible display systems, privacy or smart glass, projection devices, sensors, etc.). 

Polymer dispersed liquid crystal (PDLC) devices usually contain N phases as the liquid crystal material [71] and are used in vision products [72], e.g., privacy windows, projection displays [73], and direct view displays [74, 75]. Cholesteric liquid crystals have also been used [76]. All these devices relax back to the original ground state when the field is removed. Ideally such films consist of dfoplets of liquid crystal in a polymer matrix the reverse situation (reverse phase) consists of a liquid crystal continuum with polymer balls dispersed within it. The latter films are not desirable, because they do not provide reversible electrooptic effects. 

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